1. Field of the Invention
The present invention relates to transdermal dosage forms which are useful for preventing or discouraging tampering, abuse, misuse or diversion of a dosage form containing an active pharmaceutical agent, such as an opioid. The present invention also relates to methods of treating a patient with such a dosage form.
2. Background of the Invention
Transdermal drug delivery is a well known method for administering pharmaceuticals. Although a transdermal dosage form is intended to deliver drug across the skin, misuse or abuse of such a dosage form can take place by other modes, including oral, buccal, and intravenous. Such misuse may take place following an extraction procedure comprising immersing the transdermal dosage form in a solvent, such as water, alcohol, ethanol, or ether.
Transdermal dosage forms comprising both a drug and an antagonist for the drug have been previously proposed. U.S. Pat. No. 5,236,714 (Lee et al.) describes a transdermal dosage form which comprises a mixture of a drug and an antagonist for the drug. U.S. Pat. No. 5,149,538 (Granger, et al.) describes a transdermal dosage form comprising an opioid, an antagonist for the opioid releasable upon ingestion or solvent immersion of the dosage form, and a barrier means and an impermeable barrier means separating the opioid and the antagonist.
There exists a need in the art for improved designs for transdermal dosage forms which provide for the enhanced release of the adverse agent upon exposure of the dosage form to solvents, such as water, alcohol or ether.